Chapter 7 — The cortex

Building auditory objects

After the brainstem and the midbrain, the auditory pathway enters the thalamus, and from there ascends to primary auditory cortex on the superior temporal plane. We are now firmly inside the cerebrum. Everything from this point on is cortical processing — and cortical processing is qualitatively different from what came before. In the brainstem, the auditory system measured physical quantities (frequency, intensity, timing, location) and represented them with relatively faithful neural codes. In the cortex, the auditory system constructs — it groups, it segregates, it categorizes, it predicts. This movement is about that construction.